The "primary source" of information pertaining to the February 2017 death of William Grahek came from an inmate who reportedly received a confession from one of the three men present at the crime scene, according to briefs filed this month by defense attorneys.

The documents state that the inmate told police in an interview and later testified before a grand jury that 20-year-old Noah Duane Baker described to him the circumstances of the shooting that occured while he and the other men attempted to steal drugs and cash from Grahek's East Hillside residence.

The briefs, which also shed new light on the moments that led up to the shooting, were filed after prosecutors recently turned over a transcript of the grand jury proceedings to defense attorneys.

"The record from the grand jury transcript is insufficient to support the indictment for murder in the first degree," attorneys wrote. "Specifically, if believed, the allegations in the grand jury proceeding do not demonstrate the intention to kill necessary to support the charged offense."

Grahek, a University of Minnesota Duluth student, was shot inside his home on Feb. 14, 2017. The case went unsolved for several weeks until five suspects were arrested in early March.

While basic allegations surrounding the shooting were disclosed by authorities in charging the five suspects last March, the sources for much of the information that allowed the case to move forward were not previously publicly identified. Prosecutors also initially declined to disclose the identities of two key witnesses to defense attorneys, citing concerns for their safety and the integrity of the investigation.

The new documents, filed by attorneys for Davenport and King, state that it was an inmate incarcerated alongside Baker at the St. Louis County Jail who helped develop the case.

The inmate, identified only by initials I.N.G., requested to speak with investigators on an unspecified date in order to "provide information regarding the death of William Grahek in exchange for some benefit or reward," the motions state.

I.N.G. reportedly told police that Baker described going to Grahek's home with Davenport and Baker in an effort to steal a safe they believed to contain the party drug "molly," also known as MDMA, and cash.

Baker stated that they kicked down a door and confronted Grahek in the living room, ordering him to the ground, according to the account. They allegedly planned to retrieve the safe from the basement level, but Grahek refused to get down on the ground and instead began approaching the three intruders, according to the account relayed by I.N.G.

At that point, Davenport fired a gun twice, fatally striking Grahek, according to the statement. The three men ran from the house without ever reaching the basement or removing any items.

In an apparent contradiction, the defense attorneys wrote that other physical evidence presented to the grand jury indicates that Grahek was actually shot in the basement level of the residence and walked upstairs before he collapsed.

Davenport, Baker and King were indicted by a grand jury in August on two counts each of first-degree murder. The indictments allege that the trio was responsible for causing Grahek's death while committing, or attempting to commit, robbery and burglary. The charges, which can only be levied by a grand jury, carry mandatory life sentences, if convicted.

The defendants already were facing intentional second-degree murder and attempted first-degree aggravated robbery charges when the indictments were handed down. But attorneys are asking 6th Judicial District Judge Mark Munger to toss the more-serious charges.

"Despite the reliance on I.N.G., upon close scrutiny, the record is absent any credible evidence of an intention to kill William Grahek," Kassius Benson, an attorney for Davenport, wrote in his motion. "In fact, the record of the evidence before the grand jury indicates the contrary — that no intent to kill existed."

Citing the testimony of I.N.G., the attorneys wrote that the shooting appeared to come in response to Grahek's "aggressive and unexpected posturing and approach" after he refused their demands to get down on the ground.

"Noah Baker made it sound like they were scared, they had to shoot him, you know," the inmate testified, according to the motions.

Steve Bergeson, an attorney for King, wrote that the evidence arguably supports probable cause for lesser charges, but argued that the indictment must be tossed.

"In the end, the only reasonable conclusion, based upon the record of the grand jury transcript in this case," he wrote, "is that the death was the unintentional result of a botched robbery attempt; i.e. unintentional second-degree felony murder."

Prosecutors are expected to file arguments in opposition to the defense motions in the coming weeks before Munger issues a decision. Future court dates have not been set for any of the three defendants.

Settlement conferences are scheduled for the two other defendants charged in the case. Munger previously found probable cause to uphold charges against 27-year-old Xavier Alfred Haywood and 23-year-old Tara Rai Baker.

Haywood, who allegedly instructed the trio to rob Grahek and later harbored them in a Superior hotel, is charged with aiding an offender to avoid arrest. He will appear March 2.

Tara Baker, the girlfriend of Davenport and sister of Noah Baker, is accused of serving as a getaway driver. She faces charges of aiding and abetting murder and robbery, and is set to appear March 7.